This invention relates to a bed member for a vehicle, such as a truck, which is roll formed so as to have alternating channel-like ribs and valleys extending longitudinally thereof, and more specifically to a bed member having an improved tapered end structure associated with the channels so that the channels adjacent an edge of the bed are longitudinally tapered downwardly for merger into the plane defining the bottom of the bed.
To improve upon the construction of truck bed members which are formed using a conventional stamping process, the assignee of this application developed the improved truck bed structures and forming methods disclosed in U.S. Pat. Nos. 5,188,418, 5,544,932, 5,575,525, 5,730,486, 5,938,272, 6,128,815, and all of which are assigned to Pullman Industries, Inc., and are herein incorporated by reference.
In the aforesaid patents, and as illustrated in FIG. 1, there is disclosed a main floor pan or bed member 11 which was developed principally for a pick-up truck so that the bed member 11 is disposed between the side walls 12 of the truck and extends rearwardly from the front wall 13 so as to terminate at the rear sill 14. The bed member has the rear edge thereof secured, typically by welding, to the rear sill 14, and the bed member is typically supported on and fixedly secured to additional cross sills which are spaced longitudinally along the bed, such as the intermediate cross sills 15 and the front sill 16. The bed member 11 is roll formed from a continuous sheet of thin steel so as to have alternating ribs 18 and valleys 19 of channel-like cross-section disposed sidewardly thereacross with such ribs and valleys extending longitudinally along the roll formed sheet. The roll formed sheet is then cut to length to define the bed member, which bed member hence has the front and rear edges thereof having a corrugated configuration defined by the alternating ribs and valleys. In a preferred variation of this invention, the rear sill 14 is provided with protruding projections 17 on the top wall thereof, which projections interfit within the channels of the bed member 11 at the rear edge thereof to provide for a strong structural assembly while also closing off the rear ends of the ribs.
The arrangement described above and as briefly illustrated in FIG. 1 has proven to provide a highly desirable bed assembly, but in a continuing effort to provide for and accommodate other demands associated with the use of such vehicles, the assignee hereof has also developed a modified end construction for the bed member 11 which, as illustrated by FIGS. 2-5, results in the ends of the ribs 18 being flattened downwardly through a tapered or downwardly sloped rib section so as to merge with the bottom of the bed member, namely the walls which define the bottoms of the valleys, so as to effect closure of the ends of the ribs and at the same time result in the edge of the bed member being generally flat.
The construction illustrated by FIGS. 2-5, as disclosed in copending U.S. application Ser. No. 09/196,979 (now replaced by copending continuation U.S. application Ser. No. 09/611,444) owned by the assignee hereof and incorporated herein by reference, results in a modified edge construction for the roll-formed bed member 11 so as to permit the edge portion of the bed to be supported on a conventional cross sill 21 (which can be either a rear sill or a front sill) without the necessity of providing the top wall of the sill with upward projections for nesting within the channels of the ribs, although provision of such projections on the cross sill is still a preferred alternative. In this edge construction, the bed member 11 is provided with a flat and substantially planar flange 22 extending transversely across the bed member, which flange terminates at a free edge 23 of the bed member. The flange 22 is defined by deforming and hence flattening rear portions of the channel-like ribs 18 over a selected longitudinal length which projects forwardly from the free edge 23.
The bed member 11 of FIGS. 2-4 in addition has the ribs 18 thereof, just forwardly of the flange 22, downwardly deformed to define tapered rib portions 18A which extend longitudinally of the bed member over a small longitudinal distance, and define a transitional zone between the rear flange 22 and the longitudinally-extending full-height rib 18. The tapered rib portions 18A each have a top wall 25A which at one end is continuous with and joins to the top wall 25 of the full-height rib 18, with the top wall 25A then angling or sloping downwardly as it projects longitudinally until intersecting the plane of the bed member base walls 26 (the latter defining the bottom of the valleys 19), which intersection substantially defines the transition between the tapered rib portions 18A and the rear flange 22. The tapered rib portions 18A thus effectively define a slope or ramp which projects upwardly from the elevation of the base walls 26 or flange 22 to the elevation of the rib top walls 25, with the ramp projecting in a longitudinal direction which, when the tapered rib portion is at the rear edge of the bed member, slopes upwardly in the forward direction of the bed member to thus eliminate or minimize any abrupt or sharp corners at the rear edge of the bed member.
The tapered rib portions 18A are shaped by physically deforming a selected length of the full-height ribs 18 downwardly into the tapered or sloped configuration, which forming typically is carried out in a shaping press following the roll forming of the bed member. The deforming (i.e. compressing) of the ribs 18 into the tapered configuration results in at least partial collapsing of the side walls 27 of the ribs, and the tapered rib portion 18A is preferably formed so that the top wall 25A thereof extends at a slope or angle relative to the horizontal of at least about 30xc2x0, and more preferably in the neighborhood of about 40xc2x0 to about 45xc2x0, in an effort to minimize the amount of material which is being physically displaced during the compression of the ribs into the tapered shape.
During the deforming of the end portions of the ribs 18 so as to form the tapered rib portions 18A, the end portions of the ribs 18 which extend between the tapered portions 18A and the rear edge 23 are also substantially simultaneously flattened during the same deforming or pressing operation so that the rib portions which extend throughout the longitudinal length of the flange 22 are effectively flattened so as to be substantially coplanar with the base walls 26 and thereby result in the substantially flat and planar edge flange 22.
With the arrangement as illustrated by FIG. 2, the flange 22 can be positioned so as to lie flatly on an upper surface of the cross sill so as to permit closure and fixed securement therewith.
Alternatively, the flattened rear flange, designated 22A in FIG. 5, can be bent downwardly in the vicinity adjacent or slightly rearwardly from the intersection point with the tapered rib-portions 18A, which flange 22A can be disposed so as to project downwardly directly adjacent and hence overlap a side surface of the supporting cross sill 21, such as the rear surface when the cross sill 21 constitutes the rear sill of the vehicle bed construction. In this arrangement the flange 22A can be fixedly secured to the cross sill, such as by welding.
While the rib end constructions illustrated by FIGS. 2-5 may be desirable for some use situations, nevertheless these rib end constructions created by reforming a roll-formed bed member result in undesired wrinkling of the material during the deforming or flattening operation. In order to deform the full-height rib into either the tapered rib portion and/or the flat rear flange, it is necessary to cause the excess material which exists due to the presence of the side walls 27 to be redistributed so as to merge into the material associated with the adjacent top or bottom walls 25 and 26. Because of this excess material, stamping of the rear ends of the ribs is normally unable to effectively redistribute this excess material, and hence the tapered rib portions 18A particularly in the vicinity of the sides thereof, and particularly the flat rear flange 22 in the vicinity where the side walls 27 previously existed, often exhibit significant wrinkling due to the excess material so that the resulting wall structure not only loses its desired uniformity of thickness but also results in undesired surface characteristics which may be considered unacceptable, particularly when painting or the like.
Accordingly, in a continuing effort to improve the construction of bed members formed initially by roll forming, and which are then subjected to further forming such as pressing so as to define tapered end configurations similar to those depicted by FIGS. 2-5, the present invention relates to an improved tapered rib end configuration and an improved forming process which permits end portions of the roll-formed ribs to be subsequently deformed, as by stamping, and which improved construction and process eliminates or at least greatly minimizes undesired wrinkling by permitting more effective redistribution of excess material during the deforming operation, and which in addition provides the resulting tapered rib portion with increased strength and rigidity.
The improved construction of the present invention, and advantages resulting therefrom, will be apparent upon reading the following specification and inspecting the accompanying drawings.